Generally, a light deflector for use in a scanner apparatus of a laser printer or the like includes a polygon mirror. However, in recent years, a light deflector including a MEMS (Micro Electro Mechanical System) mirror instead of the polygon mirror has been proposed (e.g., refer to JP-A-2004-198500).
The MEMS mirror is one of products in the field of the micro electrical mechanical systems, which are manufactured by applying a semiconductor process technology. Generally, the MEMS mirror has a rotationally oscillating plate formed by cutting out a planar substrate, in which a total reflection mirror face is formed in the center of the surface by means of evaporation and so on. And the oscillating mirror including this rotationally oscillating plate is supported by the substrate to be rotated and oscillated (vibrated) about a shaft portion cut and left on the central line as the shaft.
A MEMS mirror, which is driven by an electromagnetic drive method among the MEMS mirror of this type, includes a plane coil around the mirror face on an oscillating mirror and a permanent magnet generating a magnetic field to the plane coil, on the substrate surrounding the oscillating mirror.
The MEMS mirror of this type, which is driven by an electromagnetic drive method, supplies a predetermined drive signal to the plane coil on the oscillating mirror via a wiring drawn out from the substrate, and generates the Lorenz's force in accordance with the drive signal to rotate and drive the oscillating mirror.